The objectives of this proposal are to reveal the molecular mechanisms of NE cell differentiation in the prostate, characterize new markers for future clinical applications, and help clarify the biological significance of this phenomenon. The aims are to 1) determine the changes in gene expression involved in the process of in vitro-induced NE differentiation of CaP cells; 2) molecularly and functionally characterize thyroid stimulating hormone (TSH)-like peptide, one of the most abundant peptides in NE differentiation of CaP cells; and 3) determine the proliferation status of the induced NE cells and their paracrine effects in co-culture on CaP cell lines in the absence and presence of androgens.